速度换算器

使用精确系数将 mph 换算为 km/h、km/h 换算为 mph，以及 m/s 和节；还支持 ft/s、海平面马赫数和光速。

更新于 2026年9月29日已验证的示例：5

转换后的数值

km/h

有效数字：12；取最近值，等距时远离零

换算: 60 mph = 96.56064 km/h
换算系数: 1.609344
精确性: 精确

60 mph精确等于96.56064 km/h。一个英里每小时精确等于1.609344 km/h。

用各个单位表示同一个量

60 mph用各个速度单位表示行数：8

单位	数值	定义
米每秒 (m/s)	26.8224	基本单位
千米每小时 (km/h)	96.56064	1 km/h = 1,000/3,600 m/s，精确值
英里每小时 (mph)	60	1 mph = 0.44704 m/s，精确值
节 (kn)	52.13857	1 kn = 1,852/3,600 m/s，精确值
foot per second (ft/s)	88	1 ft/s = 0.3048 m/s，精确值
kilometre per second (km/s)	0.0268224	1 km/s = 1,000 m/s，精确值
Mach (sea level) (Ma)	0.07882125	1 Ma = 340.294 m/s，近似值（海平面 ISA 空气中的声速，15 °C）
speed of light (c)	8.94699 × 10⁻⁸	1 c = 299,792,458 m/s，精确值

计算方法 S

将英里每小时换算为米每秒
$60\ \text{mph} \times 0.44704\ \tfrac{\text{m/s}}{\text{mph}} = 26.8224\ \text{m/s}$
1 mph = 0.44704 m/s，精确值
将米每秒换算为千米每小时
$26.8224\ \text{m/s} \div \tfrac{1{,}000}{3{,}600}\ \tfrac{\text{m/s}}{\text{km/h}} = 96.56064\ \text{km/h}$
1 km/h = 1,000/3,600 m/s，精确值
合并换算系数
$1\ \text{mph} = \frac{0.44704}{\tfrac{1{,}000}{3{,}600}}\ \text{km/h} = 1.609344\ \text{km/h}$
两个单位的定义都精确，且换算结果为有限小数，因此显示的每一位数字都精确。

关于速度换算器

Each speed unit is a fixed number of metres per second. The road and sea units are exact: a mile per hour is 0.44704 m/s because the mile is 1,609.344 m, a kilometre per hour is 1/3.6 m/s, and a knot, one nautical mile per hour, is 1,852/3,600 m/s.

The default converts 60 mph to 96.56064 km/h, the figure a UK or US driver needs on metric roads. Sailors and pilots work in knots, and 1 knot is exactly 1.852 km/h.

Mach is fixed here at 340.294 m/s, the speed of sound in the International Standard Atmosphere at sea level and 15 °C, and results that use it are marked approximate because the real speed of sound falls with temperature. The speed of light is exactly 299,792,458 m/s by definition.

计算示例

60 mph in km/h

数值: 60 mph
从: mile per hour (mph)
到: kilometre per hour (km/h)

转换后的数值: 96.56064 km/h
精确性: 精确

核验来源：60 × 1609.344 m / 1000 = 96.56064 km/h (1 mi = 1609.344 m, NIST HB 44)

1 knot in km/h

数值: 1 kn
从: knot (kn)
到: kilometre per hour (km/h)

转换后的数值: 1.852 km/h

核验来源：1 knot = 1 nautical mile per hour = 1852 m/h (NIST SP 811 App. B)

100 km/h in m/s

数值: 100 km/h
从: kilometre per hour (km/h)
到: metre per second (m/s)

转换后的数值: 27.7777777778 m/s
精确性: 定义精确，结果为循环小数

核验来源：100000 m / 3600 s = 250/9 (Python 3.8 fractions from the legal definitions)

Speed of light in km/s

数值: 1 c
从: speed of light (c)
到: kilometre per second (km/s)

转换后的数值: 299,792.458 km/s

核验来源：c = 299,792,458 m/s exactly (SI definition of the metre)

常见问题

How do I convert mph to km/h?

Multiply by 1.609344: 60 mph × 1.609344 = 96.56064 km/h, and 70 mph is 112.65 km/h. The factor is exact because a mile is exactly 1,609.344 m. Multiplying by 1.6 is a mental shortcut that comes out 0.6% low; to go from km/h to mph, multiply by 0.621371.

How do I convert km/h to m/s?

Divide by 3.6, because an hour has 3,600 seconds and a kilometre 1,000 metres. 100 km/h is 27.78 m/s and 36 km/h is exactly 10 m/s. Multiply by 3.6 to go back: a sprinter at 10 m/s is running 36 km/h, or 22.37 mph.

What is a knot in mph and km/h?

One knot is exactly 1.852 km/h, about 1.15078 mph or 0.514444 m/s. It is one nautical mile (1,852 m) per hour, the speed unit of shipping and aviation, so a 30-knot wind is 55.56 km/h or 34.52 mph.

How fast is Mach 1?

In the International Standard Atmosphere at sea level (15 °C) it is 340.294 m/s, which is 1,225.06 km/h or 761.22 mph, the value this converter uses. The speed of sound depends on air temperature, so at 11 km altitude, where the standard atmosphere is −56.5 °C, Mach 1 is about 295 m/s or 1,062 km/h.

Why is the speed of light an exact number?

Because the metre is defined from it. Since 1983 the metre has been the distance light travels in vacuum in 1/299,792,458 of a second, which fixes c at exactly 299,792,458 m/s, or 1,079,252,848.8 km/h. Converting c into any unit here is therefore exact.

“速度换算器”有多准确？

准确性取决于输入值和方法的假设。十进制运算使用50位有效数字，但估算、数值方法和源数据的精度可能较低；显示时的舍入并不能消除这些限制。已按独立来源核验的计算示例：5。例如，“60 mph in km/h”根据60 × 1609.344 m / 1000 = 96.56064 km/h (1 mi = 1609.344 m, NIST HB 44)进行核验。

这种方法出自哪里？

NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors; NIST Handbook 44, Appendix C — General tables of units of measurement.

关于此计算器

\begin{gathered} x_{\text{to}} = x_{\text{from}} \times \dfrac{f_{\text{from}}}{f_{\text{to}}} \\ f = \text{one unit expressed in } \text{m/s} \end{gathered}

来源

已对照来源验证

此计算器包含 5 个已解示例，答案来自独立来源。这些示例会在测试套件中运行，你也可以在此运行验证。